In many animal cell systems sodium ion is specifically required for the transport of sugars, amino acids, and other classes of compounds. I will investigate the mechanism underlying the sodium stimulation of transport of the amino acid, glutamate, in the bacterium, Escherichia coli. My overall objectives are to understand this phenomenon at both the physiological and genetic levels and to inquire into its generality in the bacterial world. The proposed approach involves kinetic studies of solute fluxes in non-growing and growing bacteria and genetic recombination studies employing conjugation and transduction.